Generally, breast cancer is the most common carcinoma in the Western countries, and also has a high frequency of occurrence together with cervical cancer and stomach cancer for Korean women. To diagnose breast cancer, mammography is generally used as a primary diagnosis. The mammography has been widely used since it has an advantage in that a diagnosis can be very simply made. However, if the tissue of the breast is very dense, diagnostic sensitivity and specificity are considerably lowered. Especially, in case of Korean women, since the tissue of the breast is denser than that of Western women, the effectiveness of the mammography is greatly lowered and diagnosis of breast cancer is very difficult.
Recently, instead of the mammography, an ultrasonic examination has been introduced and used. The ultrasonic examination does not involve a risk of radiation, and can diagnose a small tumor having a size of 2 to 3 mm due to significant improvement of image processing technology. Conventional ultrasonic examination methods include an examination method in which an inspector holds an ultrasonic probe of about 5 centimeters and moves it on a desired region of a standing subject to be examined. However, the method requires much time and manpower for carrying out the examination, and is very inefficient for mass screening examination. Further, such an examination process gives physical fatigue to an inspector and causes a subject to feel discomfort and shame. Furthermore, since the inspector moves the ultrasonic probe with his/her hand to perform the examination, only the inspector can know information on an examined location of an object to be examined. Thus, this may cause incorrect recordation of examination results. In addition, there are problems in that the examination process depends mostly on subjective evaluation by the inspector and reliability may be lowered unless the inspector has much skill in the examination. Moreover, the ultrasonic probe should be completely in close contact with the object to be examined to correctly perform the examination. However, when the examination is carried out, the ultrasonic probe and the object to be examined are not completely in close contact with each other so that a gap is formed therebetween and the results of diagnosis becomes very incorrect. In particular, in a case where the subject maintains a standing posture during the examination, since an upper side of the breast is pressed while a lower side thereof is supported, the subject feels a pain so that the subject may tend to avoid the examination. Further, in a case where the subject lies on his/her back or stomach during the ultrasonic examination, since the examination procedure is very complicated, the efficiency of the examination apparatus is lowered. Moreover, since the subject goes through an examination in an uncomfortable posture, the subject feels physical fatigue.
International Patent Application Publication No. WO 83/02053 discloses an apparatus capable of performing an ultrasonic examination of a deformable object, wherein the breast is placed on an ultrasonically transparent plate through which ultrasonic waves can pass and an ultrasonic sensor is moved below the plate. An object of the patent application is to provide an examination apparatus that can perform an ultrasonic examination in a posture in which the results of an X-ray examination and the results of an ultrasonic examination can be more correctly compared with each other. In the examination apparatus disclosed in the patent application, however, since the plate through which the ultrasonic waves pass has not sufficient rigidity, deformation occurs when the breast is placed on the plate. Therefore, there is a drawback in that correct location information on the examination results cannot be obtained. If the thickness of the plate through which the ultrasonic waves pass is increased in order to prevent deformation, there are drawbacks in that an image is not clear and examination results are incorrect.